The Chinese people are often stereotyped as being inscrutable, meaning "difficult to fathom or understand." And that about sums up my reaction to yesterday's news that the flight controllers at the Chinese National Space Administration intentionally sent the Chang'e 1 orbiter crashing into the Moon.

According to this report from the Xinhua news agency, ground zero was 1.50° south, 52.36° east. That's a nondescript tract of Mare Fecunditatis about 90 miles (145 km) from the crater Messier.

The spacecraft, which carried eight experiments, rocketed toward the Moon on October 24, 2007, and had been in lunar orbit for 16 months. And it was beefy, weighing in at more than 2 tons. That's comparable to the mass of a Centaur rocket that NASA's hopes to drill into one of the lunar poles later this year, along with the LCROSS spacecraft. Chang'e 1's impact undoubtedly made a sizable splash that should have been observable from Earth.

So here's what I don't understand:

(1) The end came at 8:13 Universal Time, which is 4:13 p.m. in Beijing's time zone. That means the Moon was up, but sunset was still about two hours away — not ideal conditions for lunar observing.

(2) The near-side impact site was in daylight, yet the crash would have been closer to the terminator, or even in shadow, just a couple days ago. So why pick March 1st and not February 27th?

(3) NASA officials are lining up an army of telescopes to try to record the LCROSS finale, now scheduled for early September or thereabouts. Wouldn't it have made sense for Chinese scientists to alert their Western colleagues of Chang'e 1's impending crash? At the very least, it would have been a useful test exercise.

Maybe I'll get answers to some of these questions in three weeks, when I head to Houston for the annual Lunar and Planetary Science Conference. A contingent from the Chang'e 1 project will be there to present results from the mission.